2024-04-26 17:48:48
Thousands of Earth-like planets have been discovered so far. Lisa Kaltenegger is looking for signs of life there. The astronomer tells us in an interview whether there are any.
Are we alone or is there someone out there? Lisa Kaltenegger investigates this question. Kaltenegger is one of the world’s most renowned researchers looking for traces of extraterrestrial life. It observes and examines planetary systems light years away. And this search is currently entering its most exciting phase, says Kaltenegger. In an interview with t-online, she explains why and how she and her colleagues do it.
t-online: Ms. Kaltenegger, hand on heart, are you an alien?
Lisa Kaltenegger: Unfortunately not. This would make the search for extraterrestrial life much easier.
Anyone can claim that they are not an alien. How can I tell if you’re telling the truth?
If we look at all people here on earth, they all have DNA with the same building blocks. This includes carbon and we need water. That means either we are all aliens or none of us are. And that’s how science does it. If you found someone whose DNA was made up of different building blocks than ours, with different bases and atoms, then that life would be different from all others. And we could assume that this life would probably not have originated here on Earth, but somewhere else. But since my DNA is made of the same building blocks as yours, I can conclude that you and I are earthlings and not aliens.
To person
The native Austrian Lisa Kaltenegger is an astrophysicist and astronomer. She is the founder and director of the Carl Sagan Institute at Cornell University in New York State, where she is also a professor of astronomy. Kaltenegger was a member of the National Science Foundation’s Astronomy and Astrophysics Advisory Committee (AAAC), which advised the US government. Kaltenegger also works with NASA and the European Space Agency Esa. The asteroid “7734 Kaltenegger” was named after her.
Well, I believe you. Let’s ask it directly: Is there hope that we will find alien life in space?
With the James Webb Telescope we are able for the first time to capture the light of other planets that could be like our Earth and search for traces of life there. We know that such a planet orbits around every fifth star – and in our galaxy alone, the Milky Way, there are around 200 billion stars. That doesn’t mean that there has to be life in the cosmos, because we don’t know how easy or difficult it is to create life. But there are theoretically billions of possibilities for planets like ours. When I look at the sky in the evening, I like to imagine that someone out there might be looking at the sky and wondering whether there is other life in the universe.
The question of whether we are alone is a central question for humanity. Why is it so important for us to find out?
We are generally very curious and social creatures. Wouldn’t it be exciting to find out what’s going on around us and whether there might be someone or something else there? When you look out into the vastness of the universe in the night sky and see all these other stars, it can sometimes feel pretty small, but now we know that there are planets orbiting around these stars too. That also makes the vastness of space more inviting.
Unfortunately, the Earth is not a globe in a protected glass sphere.
Lisa Kaltenegger
Why should space tempt us when we have enough problems of our own?
Precisely because the Earth is unfortunately not a globe in a protected glass ball. Rather, we are part of the universe, of our cosmic neighborhood. This means that we should know our surroundings well – also to avoid any dangers. The dinosaurs probably would have liked a space program like NASA’s Dart mission, which is currently learning how to divert asteroids from their orbit and can prevent asteroids from potentially impacting Earth.
Is there any evidence that there is life out there in our environment?
We have not yet discovered any signals that show life on other planets – neither single-celled organisms nor civilizations. But for the first time we have a telescope large enough to begin this search. And that’s why scientists from different disciplines have to think about what these signals could look like so that we don’t miss them. But such a signal would raise many more questions: How could we communicate with another species? What would contact mean for us as humanity? There are already many ideas about this.